What Are the Dangers of Eating an All-Vegetable Diet?

by Nina K.

Vegetables may be nutritious, but you need a balanced diet for good health.

While you may enjoy perfect health on a varied, well-planned vegetarian diet, restricting food choices to vegetables only can have serious health consequences. With no other food groups, it's not only likely that you won't get the energy you need to fuel everyday activities, but you might also become deficient in an assortment of nutrients. To promote good health, include foods such as fruits, nuts, legumes and whole grains in your diet -- all of which qualify as vegetarian and vegan -- along with plenty of vegetables.

Calorie Deficiency

Most moderately active men burn between 2,400 and 2,800 calories per day, while most women burn 1,800 to 2,200 calories. It's extremely difficult to meet these numbers with vegetables alone. For example, 1 cup of raw, chopped carrots contains just 52 calories, while the same amount of boiled broccoli contains 55 calories. You'd need to eat 38 cups of carrots or 36 cups of broccoli just to consume 2,000 calories. With too few calories, you'll likely feel lethargic and have a harder time focusing and performing vigorous activities.

Macronutrient Deficiency

Although vegetables are good sources of fiber and carbohydrates, they lack significant amounts of the macronutrients, fat and protein. Fat is necessary for healthy mental function, energy and nutrient metabolism, while you need protein for strong muscles and an effective immune system. The "2010 Dietary Guidelines for Americans" recommends getting 20 to 35 percent of your daily calories from fat and 10 to 35 percent from protein. Beans, peas and tofu are good protein sources, while nuts, avocado and olive oil are healthy sources of fat.

Vitamin and Mineral Deficiency

With a vegetable-only diet, you'll miss out on the broad range of vitamins and minerals present in a balanced meal plan. In particular, you may grow deficient in vitamin B-12 and vitamin D. You also run the risk of an iron deficiency. Even though some vegetables, such as dark, leafy greens, are rich in iron, they also contain chemicals called phytates that block absorption of the mineral. A diet deficient in vitamin B-12 or iron can cause anemia, a condition in which your blood doesn't supply your body with enough oxygen.

Disordered Eating

Severely restricting food can be a sign of an eating disorder, particularly if you are trying to lose weight. Healthy weight loss does not involve drastic calorie reduction -- and putting your physical image over your well-being could be a sign of deeper issues. Only a qualified health professional can diagnose such a condition. However, if you feel overwhelmed by your weight or your diet, speak with a counselor or other expert to help ensure optimal physical and mental health.

What's your dietary preference?

Gluten Free

Omnivore

Paleo

Vegetarian

Vegan

Which of these foods do you like to eat?

Fruit

Legumes

Meat & Poultry

Fish

Nuts & Seeds

Vegetables

Healthy fats

What kinds of foods would you like to incorporate more in your diet?

Healthy fats

Vegetables

Meat, Poultry & Fish

Grains

Fruits

Which of these fats do you like?

Olive oil

Avocados

Salmon

Olives

Sesame oil

Almonds

Which of these vegetables do you like?

Broccoli

Kale

Carrots

Peppers

Sweet potatoes

Which of these proteins do you like?

Beef

Chicken

Tilapia

Turkey

Eggs

Pork

Which of these grains do you like?

Whole wheat

Brown rice

Oatmeal

Cous Cous

Bulgar

Which of these fruits do you like?

Apples

Bananas

Pears

Kiwis

Oranges

Peaches

Pomegranates

Berries

Which of these foods do you like to eat?

Fish

Nuts

Vegetables

Meat & Poultry

Fruits

These are kinds of fish you can eat on a Paleo diet. Which do you like?

Halibut

Red Snapper

Tilapia

Salmon

These are some nuts you can eat on a Paleo diet. Which do you like?

Almonds

Cashews

Pistacios

Walnuts

These are some vegetables you can eat on a Paleo diet. Which do you like?

Broccoli

Peppers

Kale

Carrots

Lettuce

Cabbage

These are some proteins you can eat on a Paleo diet. Which do you like?

About the Author

Nina K. is a Los Angeles-based journalist who has been published by USAToday.com, Fitday.com, Healthy Living Magazine, Organic Authority and numerous other print and web publications. She has a philosophy degree from the University of Colorado and a journalism certificate from UCLA.

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